1. Field of the Invention
The invention disclosed herein relates to a method and apparatus for punching holes in continuously moving board material.
2. Description of the Prior Art
Known methods and apparatuses for punching non-elongated holes in board material utilize reciprocating motion. Flat press plates having pins thereon are reciprocated to press the pins into the board while the board is held stationary, the board being moved between each press of the plate. While the holes thus produced are non-elongated, the board is not moved continuously which results in a generally slower operation when compared to a continuously moving board system. Also, a generally more complex system is required to start and stop the motion of the board and to synchronize the board and press motion in a reciprocating press system than in a continually moving board system. U.S. Pat. No. 3,538,797 issued in the name of the assignee herein, discloses a continuous system using a rotating drum with pins mounted thereon. However, the system disclosed in the aforementioned patent, while speeding up the hole punching operation by continuously moving the board, produces holes which are somewhat elongated. In many instances such elongation in the holes is considered aesthetically unsatisfactory. The invention disclosed herein provides for the continuous movement of the board and produces punched board with no or negligible elongation of the holes. Also, additional advantages are realized by the instant invention as will be apparent hereafter.